diff options
| -rw-r--r-- | src/librustc_mir/interpret/intern.rs | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/src/librustc_mir/interpret/intern.rs b/src/librustc_mir/interpret/intern.rs index c7545b7101c..f0d64e217a2 100644 --- a/src/librustc_mir/interpret/intern.rs +++ b/src/librustc_mir/interpret/intern.rs @@ -147,13 +147,13 @@ for // Handle trait object vtables if let Ok(meta) = value.to_meta() { if let ty::Dynamic(..) = self.ecx.tcx.struct_tail(referenced_ty).sty { - if let Ok(vtable) = meta.unwrap().to_ptr() { - // explitly choose `Immutable` here, since vtables are immutable, even - // if the reference of the fat pointer is mutable - self.intern_shallow(vtable, Mutability::Immutable)?; - } + if let Ok(vtable) = meta.unwrap().to_ptr() { + // explitly choose `Immutable` here, since vtables are immutable, even + // if the reference of the fat pointer is mutable + self.intern_shallow(vtable, Mutability::Immutable)?; } } + } let mplace = self.ecx.ref_to_mplace(value)?; // Check if we have encountered this pointer+layout combination before. // Only recurse for allocation-backed pointers. @@ -174,8 +174,14 @@ for (InternMode::Static, hir::Mutability::MutMutable) => {}, // we statically prevent `&mut T` via `const_qualif` and double check this here (InternMode::ConstBase, hir::Mutability::MutMutable) | - (InternMode::Const, hir::Mutability::MutMutable) => - bug!("const qualif failed to prevent mutable references"), + (InternMode::Const, hir::Mutability::MutMutable) => { + match referenced_ty.sty { + ty::Array(_, n) if n.unwrap_usize(self.ecx.tcx.tcx) == 0 => {} + ty::Slice(_) + if value.to_meta().unwrap().unwrap().to_usize(self.ecx)? == 0 => {} + _ => bug!("const qualif failed to prevent mutable references"), + } + }, } // Compute the mutability with which we'll start visiting the allocation. This is // what gets changed when we encounter an `UnsafeCell` |